averaging + covariance toolbox
removed thresholding
Cleanup
Merge branch 'master' of https://github.com/mne-tools/mne-cpp
Merge branch 'master' of https://github.com/LostSign/mne-cpp
CHG: ChannelComboBoxItemsSeclection update Butterfly
Merge branch 'master' of https://github.com/mne-tools/mne-cpp
Merge branch 'master' of https://github.com/GBeret/mne-cpp
chg: progressbar,
test: multichannel